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| author | Eric Dumazet <edumazet@google.com> | 2023-02-17 21:24:54 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-02-20 14:39:59 +0300 |
| commit | 5f1eb1ff58ea122e24adf0bc940f268ed2227462 (patch) | |
| tree | 9e570cd6d4c78167faf5aa6a2b5f618ff093046b /net/core | |
| parent | fce10282a03db59bdb1cba6333d0564461d47bd6 (diff) | |
| download | linux-5f1eb1ff58ea122e24adf0bc940f268ed2227462.tar.xz | |
scm: add user copy checks to put_cmsg()
This is a followup of commit 2558b8039d05 ("net: use a bounce
buffer for copying skb->mark")
x86 and powerpc define user_access_begin, meaning
that they are not able to perform user copy checks
when using user_write_access_begin() / unsafe_copy_to_user()
and friends [1]
Instead of waiting bugs to trigger on other arches,
add a check_object_size() in put_cmsg() to make sure
that new code tested on x86 with CONFIG_HARDENED_USERCOPY=y
will perform more security checks.
[1] We can not generically call check_object_size() from
unsafe_copy_to_user() because UACCESS is enabled at this point.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/scm.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/core/scm.c b/net/core/scm.c index 5c356f0dee30..acb7d776fa6e 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -229,6 +229,8 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data) if (msg->msg_control_is_user) { struct cmsghdr __user *cm = msg->msg_control_user; + check_object_size(data, cmlen - sizeof(*cm), true); + if (!user_write_access_begin(cm, cmlen)) goto efault; |